The Twin Towers Correctional Facility and adjacent Central Arraignment Court in Los Angeles went on lockdown, and an area search launched, after a civilian employee reported to her supervisor about 8:45 a.m. that she saw "somebody outside who resembled suspect Dorner," Los Angeles County Sheriff's Department spokeswoman Steve Whitmore said.

"Out of a preponderance of caution, we locked down the facility as well as the streets in front," Whitmore said.

The search was called off about 11:30 a.m. after investigators determined, "It was a false alarm," Whitmore said.